Automatic telephone system



July 7, 1931.

J. wlcKs AUTOMATIC TELEPHQNE SYSTEM Filed Aug. 23, 1930 I mmzmz umm zwm I I I is released. The switching operation takes Patented July 7, 1 931- UNITED STATES PATENT oFrrcE JOHN WICKS, 02F OAK PAR-K, ILLINOIS, ASSTGNOR TO RESERVE HOLDING COMPANY,

=01 CHICAGO, ILLINOIS, A COE-IPORATION 'OF DELAWARE AUTOIVIATIC TELEPHONE SYSTEM Application filed August 23, 1930.. Serial No. 477,214.

a call, is connected with a selector repeater at the branch exchange, and a branch conneat-ion is simultaneously extended over a trunk line to an incoming selector in the main exchange. -The selector repeater and the incoming selector operate in synchron is'm in'response to the dialled impulses, and when sufiicient digits have been dialled to de termine the ultimate destination of the call, either the selector repeater is disabled for r ther operation or the branch connection place and is controlled by the selector repca ter according to the number called.

Several methods of initiating the switchperati'on of the selector repeater are in common 'us'e. One method consists of wiring "the select-or repeater banks in a partical-ar manner, so that the switching operationtztkes place when the switch wipers are positioned on certain sets of contacts. Another arrangement employs shaft springs which initiate the switching operation when the switch wipers are raised to a particular level The firstfarrangement requires a compliicatecl and relatively expensive bank wiring, "while the second arrangement lacks flexibility, particularly when it is necessary to en'rpl'oy two or more digits for determinthe routing of a call.

The =above-2referred to objectionable features-are eliminated in :the present invention, whichienrpl'oys a vertical wiper and a simple vertical :c'ent ct bank individual to each solectortrep'eater for controlling the switching operati on.

whereby rotation of the switch wipers takes place when a switching level is called. This permits the wipers to restore to normal position very rapidly after the first switching digit and prevents the wipers from occupying and tying up bank contacts after the final switching digit. The switch banks may, therefore, be used to their full capacity for local service in the branch exchange.

The foregoing features together with others not specifically mentioned will be described in more detail together with the operation of the equipment, reference being had to the accompanying single figure of drawing which discloses one embodiment of the invention.

Referring now to the drawing, there is shown an ordinary automatic substation T whose associated line terminates in the lineswitch LS. Lineswitch LS may be of any well known type, for example, a rotary type lineswitch such as the one disclosed in applicants co-pending application, Serial N 0. 395,882, filed September 28, 1929. Lineswitch LS together with other similar lineswitches has access to switching selector repeaters of which the selector repeater SR is-shown. Selector repeater SR is the usual Strowger type switch having vertical and rotary movement, and in addition to the usual switch wipers is provided with a shaft wiper engaging a vertical contact bank individual to the switch. The selector repeater by way of its wipers has access to local connectors, such as the connector C. Connector C shown in skeleton form may be similar to the connector shown in the above referred to application. This connector has access to the branch-exchange subscribers lines, such as the line extending to substation Tl. Associated with the selector repeater is a lineswitch LS1 which has access to interofrice trunks connecting the main exchange and the branch exchange. One such trunk line is shown terminating in an incoming selector IS at the main exchange and an incoming selector ISl at the branch exchange. The cut-ofi relay, line relay and release relay which are the only elements of the latter switch shown in detail are similar to those of the incoming selector 100 shown in the previously referred to appliing numbers beginning with the digit three,

cation. Both incoming selector IS and ISl may be exactly the same as the incoming selector shown in the previously referred to application, and each has access to local switches in the respective exchanges. 'The trunk line is also accessible to the local switches in the main exchange for extending connections to branch exchange subscribers.

The system disclosedtoillustrate the invention is a five digit system of which one one-thousand group of numbers is assigned for branch exchange lines. The numbers assigned to the branch exchangelines are in the same ten-thousand series as certain lines of the main exchange, which makes the switching selector repeater necessary. It is assumed for convenience that the numbers of the. 34000 series are assigned to the branchexchange lines and that the remainthat is, numbers from 31000-33000 and 3500039000 are assigned to main office lines.

It is obvious, therefore, that any number excepting a 3 which constitutes the first digit designates a call as for the main exchange.

Calls for numbers beginning with a three may be either for main exchange or branch exchange lines depending on the value of the second digit.

The subscriber at substation T on initiatinga call is connected with an idle selector repeater, such as SR, by the lineswitch LS.

Lineswitch'LSl operates responsive. to the seizure of the associated selector repeater and extends a connection over an idle interofiice trunk line to an incoming selector, such as IS, at the main exchangehThe subscriber then dials the five digits of the called number to complete the connection.- In case the'first digit dialled is any otherthan three, the selector repeater wipersare raised, to the called level but'do not rotate in, and the selector'repeater is disabledefrom further operation. The incoming selector operates in synchronism with the selector repeater and selects an idle trunk extending to a local second selector in the main exchange. The

- usual way to extend the connection to the no A secondselector, third selector, and connector at the main exchange respond to the subsequent digits of the'called number in the wanted subscribers line. In case the first digit of the called number is the digit three,

the. selector repeater and incoming selector level but do not rotate and the selector repeater is disabled from further operation.

. The secondselector; atthe main exchange digit is dialled.- The automatic 'hunting'cir cuit is prepared, and, responsive to the third digit of the called number, the selector repeater will'select an idle trunk terminating in a branch exchangeconnector, such as the connector C. i The branch connection to the main exchange will be released. The'connector C will respond to subsequent digits and extend a connection to the subscribers line in the usualwayf r 1 Calls to main exchange subscribers In order to more clearly illustrate the utility of the invention, the operations involved in setting up various connections in a system embodyingthe invention willnow be described in detail. It will be assumed first that a branch exchange subscriber, such as the subscriber at substation T, is calling the main exchange subscriber (not shown) whose number is 51101.;When thereceiver is lifted at substation T a loop circuit is closed for operating lineswitch LS in the usual manner, and the lineswitch selects a,

trunk terminating in a selector repeater, for example, the trunk comprising conductors 108-111 terminating in selector repeater SR. Impulse relay3 of theselector repeater operates over the calling loop, the circuit'extending from battery, upper winding "of relay 2, right-hand winding of relay 3,.

normally closed contacts 22, conductor 108,

wiper 1040f the lineswitch, line conductor 102, through the loop at the callingsubstation,;line conductor 101, wiper 107 otthe lineswitch, trunk conductor 111, normally closed contacts 29, left-hand winding ot're lay 3, lower winding of relay 2, to ground Relay 2 is differentially wound and does not operate at this time. Relay 3 on operatlng prepares a control loop at contacts 32:: Relay 3 also closes, a circuit extending from.

ground, contacts 34, winding otrelay 4,0011:

tacts 43, 66, and '92, winding of vertical magnet 15, to battery, and in parallel there-:

with, through the two windings of relay 8,

to battery. Relay 4 operates over the above circuit, but due to its relatively high resist-- ance,relay 8 and the vertical magnet do not operate at this time. Relays: on operating completes the testing circuit'for lineswitch LS1 at contacts 36, connects the holding ground to release trunk conductor 110 at: contacts 37, connects ground to the local holding circuit at contacts 38, prepares the impulsing circuit and a shunt cir'cuitfor it 3o rsregcovi self atfcontacts 39, opens the release circuit at contacts .41, and prepares a circuit for the vertical wiper at contacts 40. Ground on the local holding circuit extends by way of normally closed contacts 71-, winding of relay 13, interrupter contacts of stepping magnet 95, through the winding magnet 95, to battery. Relay 13 will operate over this circuit unless the wipers of the lineswitch are Standing on the contacts of a trunk which is in use, in which case ground from the upper armature and front contact of the release relay of the incoming selector overa conductor similar to conductor 130 and the test wiper of the lineswitch will be extended by way of conductor 127, contacts 83, '67 and 36, to the lower terminal of relay 13, thereby shunting the relay and energizing stepping magne u 95'. The stepping magnet energizes and interrupts its own circuit, advancing the wipers to the next set of contacts where the testing operation is again performed. WVhen an idle trunk is encountered for example the trunk comprising conductors 135 and 136, the test wiper o l the 'li neswitcli will find no groundand relay 13 will operate in series with magnet 95, the magnet not operating, however, due to the relatively high resistance of relay 13. Relay-13 extends the control loop of the 'selec't'orrepeater to the lineswitch by closing com-acts 81 and 85 and connects the test "wi er of the lineswitch directly to the local holding circuit of the selector repeater at contacts 84. Ground on this circuit operates cut-off :re'la'y 96 of the incoming connector which disconnects the line relay 97 from the incoming trunk, and extends the trunk conductors through to the line wipers of the l'ines'witch. It will be understood that incoming selector IS at the main exchange is provided with a bridged line-relay similar to re'lay97, which now opcrates over the control loop. The control loop incidentally extends from battery through the upper winding of differential relay 2, winding of relay 5, impulse contacts 32, normally closed contacts 24 and 87 contacts '8'1,conductor 125, upper wiper of lineswitch LS1, conductor 128, contacts 132, trunk conductor 135, through the winding of the impulse relay of incoming selector I-S of the main exchange, lower trunk conductor 136, contacts 133, conductor 129, lower wiper of lineswitch LS1, conductor 129, contacts 85 and 28, Winding of relay 6, lower winding of relay 2, to ground. Relays 5 and 6 operate in series with the line relay of the incoming selector. Relay 9 in the meantime is operated over a circuit from ground on the local holding circuit, contacts 63 and69, lower winding of relay 9, to battery. The operation of relay 5 completes a locking circuit including the upper winding of relay 9, and contacts 62 and 45 to prevent the release of this relay during the setting up of the connection.

The foregoing operations take place responsive to the initiation of a call and the apparatus is now in condition to receive the dialled impulses. The calling subscriber now dials the first digit of the called numher, that is, the digit 5, and interrupts the circuit of line relay 3 which responds in the usual manner. Each time relay 3 retracts its armature, release relay 4 is shunted at contacts 35, thereby permitting relay 8 and vertical magnet 15 to energize. Relay 8 is slow-to-release and maintains a shunt circuit around relay 6 by connecting ground directly to the control loop at contacts 56 to improve pulsing. Magnet 15 raises the wipers of the switch to the called level. The previously traced control loop which extends to the main exchange is also interrupted at contacts 32 of the line relay and the impulse relay of the incoming selector responds accordingly. The wipers of the incoming selector are, therefore, raised to the fifth level where the automatic hunting operation takes place in the usual manner. Shortly after the last impulse of the series relay 8 of the selector repeater decnergizes and completes a circuit from ground, contacts 40 and 55, vertical wiper 141, fifth contact of the vertical bank which it will be noted is multipled with the remaining contacts with the exception of the third and fourth contacts of the bank, contacts 73, winding of relay 10, to battery. Relay 10, operates, and at contact 64 completes a looking circuit for itself to ground on the local holding circuit of the selector repeater. Relay 4 is now maintained energized in series with the lower winding of relay 8, whose high resistance upper winding is short-circuited by the closure of contacts 65. No rotation of the switch wipers of the selector repeater take place under these conditions'since the circuit of rotary magnet 16 is open at contacts 68, and consequently the wipers remain positioned opposite the fifth level of the banks.

The calling subscriber now dials the second digit of the called number, assumed to be digit 1, and relay 3 responds as in the previous instance. Relay 8 again responds but has no useful function at this time aside from shunting relay 6. The control loop extending over the trunk line is interrupted at contacts 32 as in the previous instance and the second selector at the main exchange operates accordingly to select an idle third selector accessible in its first level. The operations responsive to the subsequent digits of the called number are similar to those just described and serve to operate the third selector and connector at the main exchange. In case the called line is busy, the connector will return the usual busy tone to inform the calling subscriber of this fact. In the event that the called line is idle,.the' connector. will seize the line in the usual way and the line relay at the connector. will be disconnected from the control loop, thereby. openingthe circuits of relays'5 and 6 'which" release. Relay opens the circuit of relay 9 at contacts 45, and relay 9 releases. Relay .9

' circuit at contacts 49 and 50' The meter (not shown) on the calling line energizes but does not register until'it deenergizes.

If the system is not'arranged for zone meteringfno further operations take place while the conversation is in progress. the called subscriber hangs up at the termination of the call, rclays 5 and 6 will release. Relay 3 releases when the calling subscriber hangs up and opens the circuit of relay 4. Relay 4 closes a circuit for release magnet 17 including off-normal contacts 18 which closed on the first vertical step of the wipers. The releasemagnetoperates and restores the switch wipers to normal in the usual way. Relay 8 operates from ground at contacts 42 duringthe releasing of the switch and maintains a busying ground in the release trunk atcontacts 54 to prevent seizure of the switch. The control loop extending to the main exchange is opened atcontacts 32 on the release of relay 3 and incoming selector IS and other svvltches 1n the ma n exchange.

restoreto normal in the usual way.'

In case the system is arranged for elapsed time metering, the main exchange will be provided with timing apparatus of the generaltyp'e shown in the co-pending appllca tion of Wicks and Gould, Serial No. 432,688, filed March 3, 1930. At intervals during-the course of the call, this apparatus will connect battery potential to the trunk linethereby shunting relay 5 of the selector repeater. Relay 5 on restoring will apply ground via contacts 44, 46 and 50 to thevmetering conductor, shunting the meter of the calling. line.

which will restore and register aunit charge.

The subscriber at substation T to call subscriber No. 38101, for example,'at the main office, willproceed as in the previous connection. The selector repeater and incoming selector will operatein synchronism in response to the first digit and vertical wiper 141 will come to rest on the third contact of the vertical bank. Shortly after the last impulse of the series relay 8 restores as before and'completes acircuit via contacts 40 and 55, wiper 141, normally closed contacts 78,,

When

lower winding of two-step relay 12, to bat-' tery; Relay 12 is adjustedso. that when energized over itslower winding alonecontacts 7 5 and 79 areiclosed but the remaining contacts remain in normal" position. A- circuit for operating the relay in its second step is prepared at contacts which becomes effective on the opening of theinitial operating circuit. Ground over the vertical wiper is also extendedby wayof'contacts 79 which close and contacts 80v which remain closed as is normally the case, winding of release magnet. 17, to battery.v The release magnet operates and restores the switch wipers'to normal position in the usual way. The release magnet on operating completes a circuit at contacts 42 for operating relay 8, and relay 8 in turn disconnects; ground from the vertical wiper to open the initial energizing circuit of relay 12. Relay 12, therefore, operates in its second step, connects up relay 11, and disconnects itself from the vertical bank contact. The impulses are repeated over the control loop to the lncoming selector at the'mainexchange as in the previous case and this switch operates to select an idle trunk to a second selector accessible in its third level.

The subscriber now dials the-second digit of the called number inthis case the digit 8, and a circuit is closed for relay 10 exactly as in the previous instance. Relay 10 op.- erates and disables the selector repeater for further operationythereby permitting the final digits to operate the third. selector and connector; at themain exchange as in the previous connection. 7

It will be noted that the fourth contact of the vertical bank is multipled with all of the remaining contacts of the bank with the exception of the third contact, through normally closed contacts of relay to permit the assignment of the fourth level for main exchange numbers and at the same time reserving this level for the critical second digit of branch exchange numbers.

OaZZs to branch ezvohange'subscribers main exchange are stepped to the third levelresponsive to the first digit dialled, that is, the digit 3,.and shortly after'the last impulse of the Ser estW step relay'12 is energized 12. v This isails-in, the'calljust described. The selector repeater SR-and the second selector at the .closed while the remaining contacts will remain in their normal position. Relay 11 on operating in its first step will extend the ground, from the vertical Wiper by way of contacts 72 and 74, through the winding of release magnet 17, to battery. The release magnet operates and restores the switch wipers to normal in the usual manner and also close a circuit for operating relay 8. Relay 8 in turndisconnects ground from the vertical wiper which permits relay 11 to operate in its second step over two windings in series via contacts to ground on the local holding circuit. Relay 11 on operating in its second step opens a, point in the test circuit for lineswitch LS1 at contacts 67, opens/the original energizing circuit of relay 9 at contacts 69, prepares a circuit for rotary magnet 16 at contacts 68, opens the circuit of relay 13 at contacts 71, opens the circuit of relay 10 at contacts 7 8, and opens the circui-t of the release magnet at contacts 74. Relay 13 releases following the opening of I its circuit, thereby disconnecting the control loop from the line wipe-rs of lineswitch LS1. Although the control loop is opened at this time relay 5 will remain energized over a circuit extending over contacts 32, 24, 87 and 82, resistance 143, to ground on the local holding circuit. Resistance 143- is for the purpose of preventing the unbalancing of relay 2 which would release the switch.

The selector repeater will respond in the usual way to the third digit of the called number raising its wipers to the level called, in this case, the first level. Shortly after the last impulse of the series relay 8 will restore as in the previous case and a circuit is completed from ground at contacts 37, contacts 53, off-normal contacts 19 which closed on the first vertical step of the wipers, contacts 68, 90 and 94, winding of rotary magnet 16, to battery. The rotary magnet energizes, opens its own circuit at contacts 94, and steps the switch wipers to the first set of contacts in the bank. In the event that this set of contacts is busy wiper 113 will encounter ground or the absence of potential neither of which effect relay 14. The rotary magnet will consequently reoperate and advance the wipers another step and repeat the test for the succeeding trunk. These operations will be repeated until wiper 113 finds a contact marked. idle by the presence of battery potential, at which time relay 14 will operate and open the circuit of the rotary magnet at contacts 90. Relay 14 locks in "series with the rotary magnet over its lower winding via contacts 89 to ground on the local holding circuit. The control loop will now be extended via contacts 86 and 93, wipers 112 and 114, trunk conductors 11.5 and 118, to the impulse relay of connector C. The impulse relay of connector C will operate in series with relays 5 and 6 of the selector repeater. Relay 14 will also short-circuit its upper winding at contacts 88 to place a marking ground on the seized trunk. line, and will disconnect magnet 15 from in series with relay 4 and short-circuit the high resistance upper winding of relay 8 to provide sufiicient current to maintain relay 4 operated.

Relay 3 will respond to the next digit of the called number and as before will interrupt the control loop at contacts 32 which loop, as previously stated, has been extended to the impulse relay of connector 0. The impulse relay of the connector responds in the usual way and the wipers of the switch are raised to the called level. The final digit of the called number is repeated through the selector repeater in the same manner and the wipers of the connector are advanced to the contacts of the called line.

If the called line is busy the connector will return a busy tone to the calling subscriber toindicate this condition. In case the called line is idle, the connector will seize the line in the usual way and the impulse relay of the connector will be disconnected from the control loop. Relays 5 and 6 of the selector repeater will restore as described in the previous connections, relay 5 opening the circuit of relay 9 which restores and switches over the selector repeater to talking position. When the called subscriber answers relays 5 and 6 will operate since they are in the bat tery feed circuit and the metering circuit will be prepared by the operation of relay 7 as previously described. Relays 5 and 6 will, of course, restore when the called subscriber hangs up, and when the calling subscriber restores his receiver relays 3 and 4 will restore and the selector repeater will release in the usual way. It may be noted that relay 8 operates following the restoration of relay 3 and due to its slow-to-release characteristic remains operated a short time after the release of relay 4. Relay 8 maintains a ground on the release trunk to prevent the release of the calling subscribers lineswitch until after the metering operation has taken place, and to mark the selector repeater busy during this release operation. This is for the purpose of preventing a calling line from seizing the selector repeater before the same has returned to normal.

What is claimed is:

1 Atwo-coordinate switching selectorrepeater for use in branch exchanges, said selector repeater comprising means for sw1tching a call originating in the branch exchange inwhich it is being used from the main exchange to saidbranch exchange when :sufi, ficient digits havebeen called to determine the destinationof the call, and comprising a wiper positionedsolely by the first coordinate movement ofthe selector repeater for controlling said switching means.

2. In a switching selector repeater for use in branch'exchanges, said selector repeater.

adapted when seized by a calling branch exchangesubscriber to extend a connectlon to the main exchange, wipers positioned by a vertical and rotary movement of the "selector repeater for extending a call via aflocal trunk line in the branch exchange,

switching means for releasing the main exchange connection and tor rendering the selector repeater effective to extend a connection via said wipers when sufiicient digits have been called to identify the call' as local,

and a wiper positioned solely by the vertical movement of the selector repeater for trolling said switching means. j

3. In a switching selector repeater having a set of wipers adapted to be-positioned by twocoordinatemovements to extend a con COD- .IleCtlOIl to a local trunk line, a control circuit initially extended over an 'outgoing trunk l ne responsive to the selzure of the selector repeater, and an auxiliary wiper .adaptedto be positioned .by the first coo'r} dinate movement'of the selector repeater for controlling the switch-overof said circuit from the outgoing trunk to said set of wipers. 1

. 4. In aswitching selector repeater for use in a branch exchange, said selector repeater being adapted torepeat the initial digits of a called number over"atrunk'line to opa fee erate. a series of automatics'witches in the main exchange, switching means for 'releas ing the .main exchange connection andior adapting the selector repeater to extend a connection over a localtrunk linevia' a set ofwipers positioned by a vertical and rotary stepping movement, and an auxiliary wiper positioned solely bythe-vertical stepi plng movement of the selector repeater for controlling said switching means.

5. In a telephone system, main and branch exchanges, and interconnecting trunk lines, automatic switches in the mainexchange,"a switching selector repeater accessible to calling branch exchange subscribers adapted to repeat impulses over an inter-ofiiceftrunk line to operate aseries of main exchange switches, means for simultaneously operatj ing the selector repeater in its primary movement and the first of the series of main exchange swltches responsive to the first digit of the called number, means forpremovement of the selector repeater for conmeans for determining whether a connection is to be extended over said line wipers or independent thereof, and contacts engaged by said auxiliary wiper for controlling said switching means. I o I In a telephone system, main and branch exchanges and interconnecting trunk lines, automatic switches in the main exchange, a switching selectorrepeater accessible to calling'branch exchange subscribers adapted to repeat impulses over an inter-ofiice trunk line to operate a series of main exchange switches, means for simultaneously operating the selector repeater in its primary movement and the first of the series of main exchange switches" responsive to the first digit of the called number, means for restoring the selector repeater to normal when such digit indicates a call for a subscribers line which may terminate in either exchange, and a wiper positioned only by the primary movement of the selector repeater for controlling said, last means.

8; In a telephone system, main and branch exchanges and interconnecting trunk line's, automatic switches in the main exchange, a switching selector repeater accessible to a calling branch exchange subscriber adapted to repeat impulses over an inter-ofiice trunk hne to operate a series of 'main exchange switches, means for simultaneously operating the selector repeater in its primary movement and the first of the series of switches at the main exchange responsive to the first digit'of the called number, means for releasing the selector repeater when such digit designates a line which may be in either exchange, means for simultaneously operating the selector repeater in its primary movement and the second of the series of switches'at the main exchange responsive to the second digit of the called number, means for disabling the selector repeater from further-operation when said second digit designates, a main exchange subscribers line, anda wiper positioned by the primary movement of the selector repeater for controlling said releasing'and' disabling means. 1 r

'9. In a telephone system, main' and branch exchanges and interconnecting trunk lines, automatic switches in the main exchange, a switching selector repeater accessible'to a calling branch exchange subscriber adapted to. repeat impulses over an interoifiice trunk line to operate a series; of: main exchange switches, local trunk lines accessible to. the; selector repeater, means for simultaneously operating the selector repeater in its primary: movement and the first of the series ofmain exchange switches responsive to the first digit of the called number, means forreleasing the: selector repeater when said first digit designates a line which may be in either exchange, means for simultaneously operating the selector repeater in its primary movement and the second of the series of main exchange switches responsive to the second digit of the called number, means for releasing both the selector repeater and the-v main exchange switches when said second digit designates a branch exchange line and for preparing the selector repeater to connect with one of said local trunk lines, and a wiper positioned by the primary movement of the selector repeater for controlling said releasing and preparing means.

10*. In a switching device having a set of wipers; adapted to be positioned responsive toa primary stepping movement and a secondary stepping movement, an auxiliary wiperadapted to be positioned by said primary stepping movement alone, and means controlled by said auxiliary Wiper for preparing the ,device to operate in its secondary stepping movement.

11. In a switching device having directive primary movement and automatic secondary movement, a set of wipers positioned by said two movements, and an auxiliary wiper positioned by said primary movement alone for determining whether or not said secondary movement shall take place.

12. In a switching device having directive primary movement and automatic secondary movement, a set of wipers positioned by said two movements, an auxiliary wiper positioned by the primary movement alone, means normally effective to prevent the secondary movement of the device, and means controlled by said auxiliary wiper for disabling said last means.

13. In a switchin device having directive primary movement and automatic secondary movement, a set of wipers positioned by said two movements, an auxiliary wiper positioned by the primary movement alone, means normally effective to prevent the secondary movement of the device, and means controlled by said auxiliary wiper when positioned in a particular manner for restoring the wipers to normal position and for disabling said last means.

14. In a switching device having directive primary movement and automatic secondary movement, a set of Wipers positioned by said two movements, an auxiliary wiper positioned by the primary movement alone,

\ means normally effective to prevent the sec ondary movement of the device, means controlled by said auxiliary wiper when operated to one position for restoring the switch wipers to normal, and means controlled by said auxiliary wiper when reoperated to another position for restoring the switch wipers to normal and for disabling said secondary movement preventing means.

15. In a switching selector repeater adapted to be dircctiveiy operated in its vertical movement and to rotate in search of an idle local trunk line when used in a local connection, means for directively operating the selector repeater in its vertical movement and for preventing the rotary movement when used in an interofhce connection, and means for maintaining the selector repeater in its vertically operated position until the inter-office connection is released.

16. In a switching selector repeater, vertical and rotary stepping magnets, means for operating the vertical magnet when the selector repeater is used in either local or outgoing calls, and means for operating the rotary magnet only when suflicient digits have been called to designate the call as a local one. I

17. In a switching selector repeater, vertical and rotary stepping magnets, means for operating tl e vertical. magnet responsive to both first and second digits of called numbers in either local or outgoing calls, and means for operating the rotary magnet only when the second of said digits designates the call as a local one. 7

18. In a switching selector repeater, line wipers, means for raising said wipers stepby-step to a called level in both local and outgoing calls, means for rotating said wipers only in local calls, and a vertically moving auxiliary wiper for controlling said last means.

19. In a telephone system, main and branch exchanges and interconnecting trunk lines, a switching selector repeater adapted to respond to one or more digits of a called number simultaneously with switches in the main exchange, a control circuit including a source of current in the branch exchange for controlling said main exchange switches, and means in the selector repeater for re leasing the connection to the main exchange and "for extending said control circuit to a local switch in the branch exchange when suflicient digits have been called to designate the call as a local one.

20. In a telephone system comprising main and branch exchanges interconnected by trunk lines, a switching selector repeater in the branch exchange adapted to extend a control circuit to the main exchange, said circuit including a source of current in the branch exchange and one of said trunk lines, means for interrupting said circuit to operate a series of automatic switches in the main exchange, and means in the selector repeater for. SWliZClllIlgOVeI said control circuit from the trunk line extending to the main exchange to a trunk line extending to alocal switch in the branch exchange.

21. In telephone system, a main exchange and a branch exchange, a switching selector repeater in the branch exchange, means for extending a connection from the branch exchange to the main exchange reexchange, wipers for the selector repeater positioned by a vertical and rotary movement for extending a connection over a local trunk in the branch exchange, switching means in the selector repeater operative to release the main exchange connection and to transfer said impulse contacts to the local connection for controlling switching apparatus in the branch exchange, and. an auxiliary wiper for the selector repeater positioned solely by thevertical movement thereof for operating said switching means.

22.-- In a telephone system, a main exchange and a branchexchange, a switching selector repeater in the branch exchange, means for extending a connection from the branch exchange to the main exchange responsive to the seizure of the selector repeater by a branch exchange subscriber, a

, battery feed bridge in the'selector repeater included in said connection for supplying talking current to a called subscriber, wipers for the selector repeater positioned by a vertical. and rotary movementfor extending a connection over a local trunk in the branch .exchange, switching means in the selector repeater operative to release the main exchange connection and to transfer said battery feed bridge to the local connection, and an auxiliary wiper for the selector repeater positioned solely by the vertical movement thereof for operating said switching means.

23. In a switching selector repeater having a set of wipers adapted to be positioned; by two coordinate movements to extend a connection to a local trunk line, a set of imby trunk lines, aswitching selector repeater in the branch exchange adapted to initially extend a connection over one of saidtrunk lines to switching apparatus in the main exchange, a set of impulse contacts in the. se-

lector repeater for cont-rolling the main exchange switchingv apparatus over said connectlon, means for releaslng said connection and for extendlng another connection to switching apparatus in the branch exchange,

.to a called subscriber in either exchange,

means for disabling the selector repeater for further operation or for releasing the 'main exchange switching apparatus when the establishment of the connection has progressed far enough to determine in which exchange the called subscriber is located, and means in the selector repeater for feeding talking battery to a called subscriber located in either. exchange. y

In witness whereof, I hereunto subscribe my name this 19th day of; August, A. D.

. JOHN WIOKS.

pulse contacts, a control circuit including 7 said contacts extended. over an outgoing I the seizure switching trunk line responsive to of said selector repeater,

" means for transferring said impulse con- 'tacts from said first control circuit to a second control circuit including said set of wipers, and an auxiliary wiper positioned I by the first coordinate movement of said set 

